Switch assembly

ABSTRACT

A switch assembly for use in an environment requiring automatic switch operation under certain conditions, as when the switch assembly, or the body on which the switch is mounted, is tilted or changed in position beyond a predetermined amount. The assembly includes a housing in which is mounted the switch, preferably of the normally open type. A cavity is formed in the housing and has a point adjacent but spaced from the switch contact elements. Actuating means are disposed in the housing cavity and in one modification includes a magnetic member that moves away from the close adjacency to the switch contact elements when the housing is tilted beyond a predetermined amount. Thus, the switch opens until the magnetic member returns to its adjacent position, as when the housing is righted. In another modification, a magnetic member is fixed in the housing and magnetic-flux-deflecting means are pivotally mounted in the housing and in the cavity. As the housing is tilted, the deflecting means pivots into position between the magnetic member and the switch, thus deflecting the magnetic flux field. The magnetic attraction is removed and the switch opens,. When the housing is righted, magnetic flux is again established to the switch to close the switch contacts.

United States Patent [72] inventor LarsJ. Hierta' Westland, Mich. [21]Appl. No. 873,535 [22] Filed Nov. 3, 1969 [45] Patented Aug. 24, 1971[73] Assignee Western Sales Corp.

Southfleld, Mich.

[541 SWITCH ASSEMBLY 10 Claims, 7 Drawing Fig.

[52] US. Cl 335/205, 200161.52 [51] Int. Cl 1101b 36/00 [50] Field ofSearch ZOO/61.45, 61.45 M, 61.52; 335/205 [56] References Cited UNITEDSTATES PATENTS 1,175,062 3/1916 Johnson 200/61.52X 3,008,018 11/1961Hammondm. 335/205 3,330,016 7/1967 Smith, et a1. 335/205 X PrimaryExaminer-Demard A. Gilheany Assistant Examiner-R. N. Envall, Jr.Attorney- Fisher and Schmidt ABSTRACT: A switch assembly for use in anenvironment requiring automatic switch operation under certainconditions, as when the switch assembly, or the body on which the switchis mounted, is tilted or changed in position beyond a predeterminedamount. The assembly includes a housing in which is mounted the switch,preferably of the normally open type. A cavity is formed in the housingand has a point adjacent but spaced from the switch contact elements.Actuating means are disposed in the housing cavity and in onemodification includes a magnetic member that moves away from the closeadjacency to the switch contact elements when the housing is tiltedbeyond a predetermined amount. Thus, the switch opens until the magneticmember returns to its adjacent position, as when the housing is righted.In another modification, a magnetic member is fixed in the housing andmagnetic-fluxdeflecting means are pivotally mounted in the housing andin the cavity. As the housing is tilted, the deflecting means pivotsinto position between the magnetic member and the switch, thusdeflecting the magnetic flux field. The magnetic attraction is removedand the switch opens,. When the housing is righted, magnetic flux isagain established to the switch to close the switch contacts.

r qAIIlrII II/ PATENTEDMJGZMQYI 3,601,729

Y far: 1 IKizria ATTORNEYS SWITCH ASSEMBLY This invention relates toswitch assemblies, and more particularly to a switch assembly havingactuating means therein for operating a switch under conditions ofmovement of the assembly.

In the design, manufacture and use of any electrically operated devices,it is often necessary to cause a switch to acunnecessary and should beformed of a minimal number of parts and partsthat move, to keep repairsand wearing out to a minimum.

It is here proposed to provide a switch assembly for the environmentheretofore described which comprises, generally, a housing having aswitch member mounted therein and being of the normally open type, suchthat positive operation is required to close the switch contacts andwhen such actuation is removed, the switch contacts will open. A cavityis formed in the housing and having a part thereof closely adjacent butspaced from the switch member. Mounted in the cavity is the switchactuation means, which includes a magnetic member so disposed relativeto the switch contacts that when the magnetic flux is uninterrupted theswitch contacts will be closed and the circuit operative. When thehousing is tilted beyond a predetermined angle, the magnetic flux isinterrupted, weakened or removed between the magnet and the switchcontacts, thus allowing the switch contacts to open and interrupt theelectrical circuit. In one preferred embodiment of the invention themagnetic flux is interrupted by means of the magnetic member beingmovable in the cavity and rolling or sliding away from the point ofmaximum attraction of the switch contacts so that the flux is weakenedor eliminated to a point where the contacts open. In another preferredembodiment of the invention, the magnetic member is fixed in the cavityand flux-deflecting means are pivotally mounted in the housing cavity toswing between the magnetic member and the switch and provide a path ofless resistance for the magnetic flux, In either event, the actuatingmeans is located in the cavity and upon excess movement of the housingin a particular direction, the magnetic flux from the magnetic member isdisturbed or weakened to such degree as to allow the switch contacts toopen.

A switch assembly as heretofore described advantageously needs therequirements of a switch assembly in this type of environment. Themagnetic attraction is positive in its operation and so long as themagnetic properties of the magnetic member are retained, the life of thedevice is long lasting and the assembly need not be serviced. Oncemovement of the housing past the predetermined degree does occur, theflux interruption quickly and positively removes the magnetic attractionat the switch contacts and causes the switch to open. There are fewmoving parts in the device which can become fouled or worn out becauseof constant use, so that the device has little or no need for repair andreplacement of the various parts. The overall structure is easilymanufactured and assembled maintaining the costs at a minimum.

These and other objects and advantages will become more apparent fromthe following description, used to illustrate preferred embodiment ofthe invention when taken with the accompanying drawings, in which:

FIG. 1 is a transverse cross-sectional view of a switch assemblyembodying the invention and illustrating the position of the variousparts.

FIG. 2 is a transverse cross-sectional view of the switch assemblyillustrated in FIG. 1, taken substantially along the line 22 of FIG. '1and looking in the direction of the arrows.

FIG. 3 is a transverse cross-sectional view of a switch assembly inwhich the invention is embodied, illustrating the position of thevarious parts.

FIG. 4 is a longitudinal cross-sectional view of the switch assemblyillustrated in FIG. 3 and looking in the direction of the arrows. I

FIG. 5 is a transverse cross-sectional view of another switch assemblyin which the invention is embodied, illustrating the position of thevarious parts.

FIG. 6 is a longitudinal cross-sectional view of the structureillustrated in FIG. 5, taken substantially along the line 6- -6 of FIG.5 and looking in the direction of the arrows.

FIG. 7 is a transverse cross-sectional view of still another switchassembly in which the invention is embodied, illustrating the positionof the various parts.

Referring more particularly to the drawings, where the vari- A Imaterial and has mounting flanges 12 extending from the base thereofwith mounting apertures 14 extending therethrough. Thus, the housing 10may be mounted on some other assembly if such is desired.

Housing 10 may include an end plate 16 to permit the for mation andassembly of the interior parts as will be hereinafter more particularlydescribed. Mounted in the housing 10 is a switch member, indicatedgenerally by the numeral 18, which has switch contacts 20 and 22 sodisposed that when the contacts are in the engagement, an electriccurrent can flow from one contact arm 24 to the other contact arm 26 andthus through the electrical circuit or other operated object, indicatedgenerally by the numeral 28. Switch member 18 may be of the typecommonly known in the art as a reed switch, or may be of any othersuitable variety well known in the art which is provided with contactelements biased in a normally open position and one of which may beattracted by magnetic means to close contact between the two contactelements. While the particular switch structure is not critical to theinvention herein described and claimed, the reed switch best typifiesthe desirable type of switch device. Formed in the housing 10 is acavity, indicated generally by the numeral 30, such cavity havinginclined longitudinal walls 32 terminating at an apex 34 adjacent to butspaced from the reed switch element 18. The inclination of the walls 32is in a direction away from the switch 18 for purposes to becomehereinafter more apparent.

Switch actuation means are disposed within the cavity 30 and shown to bea magnetic member, indicated generally be the numeral 36. Member 36 iscylindrical in form, of slightly less diameter than the depth of thecavity 30, and may be of any suitable material, although it is preferredthat the member be a permanent magnet to maintain its long life andmagnetic attraction. It will be apparent that if the magnetic propertiesare properly computed the magnetic member 36, when disposed at the apex34 of the cavity 30, will be in a position to attract the contact member20 of the switch 18 and close the circuit through the contact arms 24and 26. The magnetic attraction of the member 36 will maintain theswitch 18 in its closed condition for so long as the magnetic member 36stays at the apex 34 of the cavity 30. However, when the housing 10 istilted, or the member on which the housing is mounted is tilted, to suchdegree that the magnetic member 36 will roll or slide along one of theinclined surfaces 32 and away from the apex 34 of the cavity 30, themagnetic flux field will be so disturbed, weakened or removed that theswitch contact arm sufficient to 20 will no longer be attracted and willseparate from the contact 22. The switch 18 will thus remain open untilthe housing 10 is righted and the magnetic member 36 rolls or slidesback down the inclined surface 32 to the apex 34. At such time themagnetic flux field is again established to the contact element 20 toclose the switch 18 and restore the electrical circuit.

Referring next to FIGS. 3 and 4, another embodiment of the the switchassembly is thereshown in which the housing, indicated generally by thenumeral 40, is provided with flanges 42 and mounting apertures 44 in amanner similar to that heretofore described. The housing may be in twoparts to include an upper portion 46 for ease in manufacture and assembly of the structure. Mounted in the housing 40 is a switch member,indicated generally by the numeral 48, similar to the switch18heretofore described with respect to the FIGS. 1 and 2.'The samerequirements are necessary of the switch 48 and the well-known reedswitch may be used. Contact element 50 and contact element 52 aredisposed within the'housing 10,

the contact arms 54 and 56 extending to the remainder of the electricalcircuit, not here shown.

A cavity, indicated generally by the numeral 60, is provided in thehousing 40-46 and has a lower wall 62 which is conical in shape. Theapex 64 of the conical wall 62 is disposed at a point adjacent to butspaced from the switch member 38. An upper wall 65 is also conicallyformed at the same angle as the wall 62, for purposes to becomehereinafter more apparent.

Disposed in the cavity 60 is a magnetic member, indicated generally bythe numeral 66, such member being conveniently spherical in shape andpreferably being a permanent magnet. It will be apparent that when thehousing 40, or the device on which it is mounted, tilts beyond aparticular degree, the magnetic member 66 will roll or slide from itsposition at the apex 64 of the conical wall 62, thus removing themagnetic attraction from the contact elements 50-52and allowing suchelements to separate and break the electrical circuit. When, the housing40 returns to its righted position, the element 66 returns to the apex64 of the conical wall 62 and reestablishes the flux field to includethe contacts 50 and 52, causing such contacts to close and therestoration of the electrical current through the contact arms 54 and56.

In the embodiment of FIGS. 1 and 2 and in the embodiment of FIGS. 3 and4, the design parameters are such that when the magnetic member 36 or 66is disposed at a point closely adjacent the switch 18 or 48, themagnetic flux field is sufficiently directed and is of sufficientstrength to attract the contact arm 28 or 50 in engagement with the arm22 or 52. When the magnetic element 36 or 66 is moved away from the apexpoint 34 or 64, the magnetic flux field is sufficiently weakened orredirected through the housing 10 to no longer attract the contact arm20 or 50 and thus cause the circuit to open. The angle of the inclinedwall 32 or the conical wall 62 relative to the horizontal axis of thehousing 10 is computed to be at such angle as desired so that a smallamount of movement may not be sufficient to cause opening of the switch18 or 48. It will be apparent that in the modification of FIGS. 1 and 2,tilting or rotation of the housing 10 only in a plane normal to the axisof the cylinder 36 will cause the cylinder 36 to move away from the apex34. In the modification of the FIGS. 3 and 4, movement in any directionbeyond the predetermined angle will be move the magnetic member awayfrom the apex 64.

Referring next to FIGS. and 6, yet another embodiment of the inventionis thereshown. A housing, indicated generally by the numeral 70, isprovided with mounting flanges 72 and mounting apertures 74, should suchbe desirable. An upper housing member 76 is provided for ease inmanufacture and assembly of the device. Disposed within the housing 70is a switch member, indicated generally by the numeral 78, which isagain preferably of the reed switch variety having an attractablecontact element 80 and a contact element 82 on contact arms 84 and 86. Acavity 90 is formed in the housing 70, and disposed in the housing andextending longitudinally through the cavity 90 is a magnetic member,indicated generally by the numeral 92. Magnetic member 92 may be 'of anysuitable material, although it is preferred that the member be apermanent magnet for long life of the device. Magnet 92 is so disposedas to be closely adjacent the switch 78 and in such position to causeattraction of the contact element into engagement with the contactelement 82. The magnetic flux field from the magnetic member 92 passesthrough the airgap between the magnet and the lower surface of thecavity and through the, material of the housing 70 to the switch member78.

Disposed within the cavity is a deflector indicated generally by thenumeral 94. Deflector 94 includes a pivot portion 96, suitably mountedin the end walls of the housing cavity for purposes to becomehereinafter more apparent. Arms 98 extend downwardly from the pivotportion 96 and terminate in arcuately inwardly directed deflectorelements 100, 'which themselves terminate in spaced relation andadjacent the magnetic member 92. The elements 100 are formed of amaterial which is more permeable to the passage of magnetic flux thanthe airgap between the magnetic member 92 and the switch 78. Suchmaterial may be soft iron or any other suitable material.

When the deflector elements 100 are in the position shown in the FIG. 5,the magnetic flux path from the magnetic member92, through the airgapand the housing, encompasses the switch contact element 80 and 82 andcauses the elements to close into current carrying condition. When thehousing 70, or the device on which it is mounted, tilts beyond apredetermined degree the deflector 94 is caused by gravity to pivotabout the pivot portion 96 and one of the elements 100 swings betweenthe magnetic member 92 and the switch 78. When thus interposed, in theflux flow path, the more permeable element 100 deflects or redirects theflux flow away from the switch member 78, thus interrupting the magneticflux path to the switch 78 and causingthe contact elements 80 and 82 toseparate and break the electrical circuit. When the housing 70 isrestoredto its normal position, the deflector 94 pivots about the pivotportion 96 so that the gap between the two deflector elements 100 isagain disposed directly between the magnetic member 92 v and the switch78. The flux flow path is reestablished to the switch member 78 and theswitch contacts 80 and 82 will close. v

Referring next to FIG. 7, yet another embodiment of the switch assemblyis illustrated in which a housing, indicated generally by the numeral110, may be provided with mounting flanges 112 and apertures 114 asheretofore described and which includes an upper cover member 116 formanufacture and assembly purposes. The switch member, indicatedgenerally by the numeral 118 and again being of the reed switch varietyas heretofore described, contains contact elements 120 and 112 on thecontact arms 124 and 126. A cavity, indicated generally by the numeral128, is formed in the body portion 110. Extending across the cavity 128and mounted in the end walls of the housing 110, is a magnetic member,indicated generally by the numeral 130, preferably being a permanentmagnet.

Depending from the upper cover member 116 is a ball 132, secured to thecover member 116 by a stem 134. Mounted on the ball 132 in any suitablemanner and for universal movement, is a conical deflector, indicatedgenerally by the numeral 136, having aligned apertures 138 formedtherein and through which pass the magnetic member 130. The size of theapertures 138 is such as to permit substantially universal movement ofthe conical deflector 136 about the ball 132 as the housing is tilted,the conical deflector will pivot about the ball 132 and a portion of themember 140 will be disposed between the magnet 130 and the switch 118.The magnetic flux field will thus be deflected, or redirected, allowingthe switch contacts 120 and 122 to open. When housing 110 is righted,the conical member 136 will again pivot about the ball 132 to place theaperture 142 between the magnet 130 and the switch 118, reestablishingthe flux field and closing the contacts 120 and 122.

In the event the switch assembly is used in an environment in whichsmall changes in orientation are often occurring, it may be desirable tofill the chamber 90 or 128 containing the flux deflecting means 94 or136 with a suitable fluid to damp movement thereof. Such fluid willprevent cycling of the switch contact with minor changes of suchdeflecting means.

Thus, a switch assembly is provided that is simple in design, easily andeconomically manufactured and produced, is positive in its operation,and has few moving parts subject to wear or replacement. The properselection of materials and proper design are easily made from materialswell known in the art and the degrees of allowable movement flux fieldstrengths required and other such parameters provide great designversatility for many applications.

What I claim is:

l. A switch assembly comprising:

a housing having a vertical axis;

switch means in said housing and located on said vertical I axis, saidswitch means being operable from a normally open condition to a closedcondition;

a cavity in said housing and spaced along said vertical axis from saidswitch means and having a portion on said vertical axis adjacent saidswitch means and extending from said vertical axis in oppositedirections;

and magnetic switch actuation means including a moveable portion, saidmagnetic actuation means being disposed in said cavity and having aposition on said vertical axis generating a magnetic flux fieldenveloping said switch means and holding said switch means in saidclosed condition, and said moveable portion moving in said cavity toremove said flux field from said switch means when said vertical axis ofsaid housing tilts beyond a predetermined amount to permit said switchmeans to operate to said closed condition. 2. The switch assembly setforth in claim 1, wherein said magnetic actuation means includes apermanent magnet moveable in said cavity from said position on saidvertical axis.

3. The switch assembly set forth in claimZ. wherein said cavity includesa wall having a point on said vertical axis and adjacent said switchmeans, said wall being angularly directed away from said switch means.

4. The switch assembly set forth in claim 3, wherein said wall is a'conehaving the apex thereof adjacent said switch means.

5. The switch assembly set forth in claim 4, wherein said permanentmagnet is spherical and adapted to move along said wall from a positionat said apex when said housing is tilted more than a predeterminedamount.

6. The switch assembly set forth in claim 1, wherein said magneticactuation means includes magnetic-flux-deflecting means moveable in saidcavity for operating said switch means.

7. The switch assembly set forth in claim 1, wherein said magneticactuation means includes a permanent magnet fixed in said housing andextending into said cavity, and magneticflux-deflecting means adapted tomove into a position for deflecting magnetic flux from said magnet awayfrom said switch means.

8. The switch means set forth in claim 7, wherein saidmagnetic-flux-deflecting means includes a portion moveable between saidpermanent magnet and said switch means, and pivot means in housing andsecured to said portion to permit movement of said portion when saidhousing is tilted.

9. The switch assembly set forth in claim 8, wherein said portionextends longitudinally of said housing.

10. The switch assembly set forth in claim 7, wherein saidmagnetic-flux-deflecting means includes a conical member pivotallysecured to said housing and in said cavity for universal movement, saidcone having aligned apertures therein receiving said permanent magnet,and an apertured member secured to said conical member and extendingbetween said permanent magnet and said switch means when said housing isin a nontilted position and said apertured member pivoting to deflectmagnetic flux flow when said housing is tilted more than a predeterminedamount.

1. A switch assembly comprising: a housing having a vertical axis;switch means in said housing and located on said vertical axis, saidswitch means being operable from a normally open condition to a closedcondition; a cavity in said housing and spaced along said vertical axisfrom said switch means and having a portion on said vertical axisadjacent said switch means and extending from said vertical axis inopposite directions; and magnetic switch actuation means including amoveable portion, said magnetic actuation means being disposed in saidcavity and having a position on said vertical axis generating a magneticflux field enveloping said switch means and holding said switch means insaid closed condition, and said moveable portion moving in said cavityto remove said flux field from said switch means when said vertical axisof said housing tilts beyond a predetermined amount to permit saidswitch means to operate to said closed condition.
 2. The switch assemblyset forth in claim 1, wherein said magnetic actuation means includes apermanent magnet moveable in said cavity from said position on saidvertical axis.
 3. The switch assembly set forth in claim 2, wherein saidcavity includes a wall having a point on said vertical axis and adjacentsaid switch means, said wall being angularly directed away from saidswitch means.
 4. The switch assembly set forth in claim 3, wherein saidwall is a cone having the apex thereof adjacent said switch means. 5.The switch assembly set forth in claim 4, wherein said permanent magnetis spherical and adapted to move along said wall from a position at saidapex when said housing is tilted more than a predetermined amount. 6.The switch assembly set forth in claim 1, wherein said magneticactuation means includes magnetic-flux-deflecting means moveable in saidcavity for operating said switch means.
 7. The switch assembly set forthin claim 1, wherein said magnetic actuation means includes a permanentmagnet fixed in said housing and extending into said cavity, andmagnetic-flux-deflecting means adapted to move into a position fordeflecting magnetic flux from said magnet away from said switch means.8. The switch means set forth in claim 7, wherein saidmagnetic-flux-deflecting means includes a portion moveable between saidpermanent magnet and said switch means, and pivot means in housing andsecured to said portion to permit movement of said portion when saidhousing is tilted.
 9. The switch assembly set forth in claim 8, whereinsaid portion extends longitudinally of said housing.
 10. The switchassembly set forth in claim 7, wherein said magnetic-flux-deflectingmeans includes a conical member pivotally secured to said housing and insaid cavity for universal movement, said cone having aligned aperturestherein receiving said permanent magnet, and an apertured member securedto said conical member and extending between said permanent magnet andsaid switch means when said housing is in a nontilted position and saidapertured member pivoting to deflect magnetic flux flow when saidhousing is tilted more than a predetermined amount.